Systems and methods for applying an antimicrobial coating to a medical device

ABSTRACT

Methods for applying an antimicrobial coating to a medical device is disclosed. Generally, the methods comprise providing a medical device, dispensing an antimicrobial coating onto the device, flushing excess coating from the device, and curing the coating onto the device. In one aspect, the coating includes a UV-curable, antimicrobial composition. In this aspect, the medical device can be coated and the coating can be cured with UV light in a manner of seconds. In another aspect, the coating includes an antimicrobial solution that contains an acrylate-type polymer or copolymer. In this aspect, the medical device can be coated and the coating can be heat-cured in a manner of minutes. Both the UV-curable composition and the antimicrobial solution can also include rheological modifiers, as necessary. Additionally, the compositions include one or more antimicrobial agents, which may be selected from a wide array of agents.

RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent ApplicationNo. 61/118,988, filed Dec. 1, 2008, entitled “Antimicrobial Compositionsand Methods for Medical Product Use;” the entire disclosure of which isincorporated herein by this reference.

BACKGROUND OF THE INVENTION

The present invention relates to systems and methods for usingantimicrobial coatings in various medical applications. One of the majorchallenges of modern medical treatment is control of infection and thespread of microbial organisms.

One area where this challenge is constantly presented is in infusiontherapies of various types. Infusion therapy is one of the most commonhealthcare procedures. Hospitalized, home care, and other patientsreceive fluids, pharmaceuticals, and blood products via a vascularaccess device inserted into the patient's vascular system. Infusiontherapy may be used to treat an infection, provide anesthesia oranalgesia, provide nutritional support, treat cancerous growths,maintain blood pressure and heart rhythm, or for many other clinicallysignificant uses.

Infusion therapy is facilitated by a vascular access device. Thevascular access device may access a patient's peripheral or centralvasculature. Additionally, the vascular access device may be indwellingfor a short term (e.g., days), a moderate term (e.g., weeks), or a longterm (e.g., months to years). The vascular access device may also beused for continuous infusion therapy or for intermittent therapy.

A common vascular access device is a plastic catheter that is insertedinto a patient's vein. Generally, the length of such a catheter may varyfrom a few centimeters, for peripheral access, to many centimeters, forcentral access. The catheter may be inserted transcutaneously or may besurgically implanted beneath the patient's skin. The catheter, or anyother vascular access device attached thereto, may have a single lumenor multiple lumens for infusion of many fluids simultaneously.

The vascular access device commonly includes an adapter (e.g., a Lueradapter) to which other medical devices may be attached. For example, anadministration set may be attached to a vascular access device at oneend while an intravenous (IV) bag is attached at the other. Theadministration set is a fluid conduit for the continuous infusion offluids and pharmaceuticals. Commonly, an IV access device is a vascularaccess device that attaches to another vascular access device, closesthe vascular access device, and allows for intermittent infusion orinjection of fluids and pharmaceuticals. An IV access device may includea housing and a septum for closing the system. The septum may be openedwith a blunt cannula or a male Luer of a medical device.

When the septum of a vascular access device fails to operate properly orhas inadequate design features, certain complications may occur.Complications associated with infusion therapy may cause significantmorbidity and even mortality. One significant complication is catheterrelated blood stream infection (CRBSI). An estimate of 250,000-400,000cases of central venous catheter (CVC) associated blood streaminfections (BSIs) occur annually in US hospitals.

Current vascular access devices prevent complications, such as infectionresulting in CRBSIs, by providing a septum that functions properlyduring attachment and/or access of the vascular access device by othermedical devices. Septa that function properly will act, in part, asinfection barriers between the internal and external environments of thevascular access device during attachment and/or access by other medicaldevices. By functioning properly as infection barriers, septa minimizeCRBSIs and other complications.

In some cases, a vascular access device may serve as a nidus ofinfection, resulting in a disseminated BSI. This may be caused byfailure to regularly flush the device, a non-sterile insertiontechnique, or by pathogens that enter the fluid flow path through eitherend of the path subsequent to catheter insertion. When a vascular accessdevice is contaminated, pathogens adhere to the vascular access device,colonize, and form a biofilm. Many such biofilms are resistant to avariety of biocidal agents and provide a replenishing source forpathogens to enter a patient's bloodstream and cause a BSI.

Over the past few decades, it has been a common practice to use athermoplastic polyurethane solution as the carrier for an antimicrobialcoating. The solvent is usually tetrahydrofuran (THF), dimethylformamide(DMF), or a blend of both. Because THF can be oxidized very quickly andtends to be very explosive, an expensive explosion-proof coatingfacility is necessary when THF is used as the solvent. Harsh solvents,such as THF and DMF, are also highly toxic and environmentallyhazardous. Additionally, the harsh solvents tend to attack most of thepolymeric materials (i.e., polyurethane, silicone, polyisoprene, butylrubber polycarbonate, polyvinyl chloride, PET, and acrylics) that areused to produce medical devices (e.g., vascular access devices).Therefore, medical devices that are made with these materials can becomedistorted and/or form micro-cracks on their surfaces. Another issue withcoatings comprising harsh solvents is that such coatings generallyrequire a relatively long period of time (e.g., about 24 hours) for thesolvent to be completely heat evaporated. Still another issue withcoatings comprising a harsh solvent is that such solvents are difficultto apply uniformly across the surface of a medical device. Accordingly,conventional technologies using harsh solvents have persistent problemswith processing and performance.

Another conventional method for providing medical devices withantimicrobial characteristics involves the use of silver salts andelemental silver. Silver salts and elemental silver are well knownantimicrobial agents in both the medical surgical industry and generalindustries. They are usually incorporated into the polymeric bulkmaterial or coated onto the surface of the medical devices by plasma,heat evaporation, electroplating, or by conventional solvent coatingtechnologies. These technologies, however, are often very tedious,expensive, time consuming, and environmentally hazardous.

In addition, the performance of silver coating medical devices ismediocre at best. For example, it can take up to 8 hours before thesilver ion, ionized from the silver salts or silver element, can reachcertain efficacy as an antimicrobial agent. As a result, substantialmicrobial activity can occur prior to the silver coating even becomingeffective. Furthermore, the silver compound or silver element has anunpleasant color, from dark amber to black.

Accordingly, there is a need in the art for improved coatings forproviding antimicrobial capability to medical devices of various types,and particularly to devices related to infusion therapy. There is also aneed for improved methods of applying such antimicrobial coatings tomedical devices.

BRIEF SUMMARY OF THE INVENTION

The present invention has been developed in response to problems andneeds in the art that have not yet been fully resolved by currentlyavailable systems and methods for applying antimicrobial coatings tomedical devices. Thus, the described methods, systems, and compositionsare developed to reduce complications (e.g., the occurrence of CRBSIs,damage to medical devices caused by harsh solvents, environmental damagecaused by harsh solvents, etc.) by providing improved methods andsystems for coating medical devices with an improved antimicrobialcoating.

Generally, the present invention includes coating a medical device withan antimicrobial coating. The described methods can be used to coat amedical device made from a variety of materials. In some preferredimplementations, however, the described methods are used to coat medicaldevices that comprise one or more polymeric substrates, which include,but are not limited to, polycarbonate, polyurethane, polyvinyl chloride,acrylic, and combinations thereof.

The described methods can be performed with one or more of a widevariety of coatings. Nevertheless, the preferred coating is selectedfrom an ultraviolet light-(UV) curable, antimicrobial composition and anantimicrobial solution.

Where the coating comprises the UV-curable, antimicrobial composition,the UV-curable composition can comprise any suitable ingredient. In someimplementations, the UV-curable composition comprises a UV-curablematerial comprising one or more urethane- or polyester-type oligomerswith at least one acrylate-type functional group, acrylate-typemonomers, and photoinitiators. Additionally, in some implementations,the UV-curable composition further comprises one or more Theologicalmodifiers and antimicrobial agents.

Where the coating comprises the antimicrobial solution, the solution cancomprise any suitable ingredient. Indeed, in some implementations, thesolution comprises one or more solvents, coating resins, Theologicalmodifiers, and antimicrobial agents.

The described methods generally include providing a medical device,dispensing an antimicrobial coating onto a surface of the device,flushing excess coating from the device, and curing the coating onto thedevice. Of course, the methods can be modified in any suitable manner.In one example of a modification, the methods include masking a portionof the device to prevent the coating from being deposited on the portionof the medical device that is covered by the masking.

In the described methods, the coating can be dispensed onto a surface ofthe device in any suitable manner. In one example, a machine injects acalculated amount of the coating into the device.

After the antimicrobial coating has been applied to the medical device,excess coating, if any, can be removed from the device in any suitablemanner. For example, the excess coating can be removed by blowing theexcess coating from the device with an inert gas, spinning the medicaldevice in a centrifuge, by wiping the device with a material, throughgravity, etc. In some presently preferred implementations, however,nitrogen gas is used to blow the excess coating from the medical device.

With the excess coating removed from the medical device, the coating canbe cured in any suitable manner. For example, the UV-curable compositioncan be rapidly cured through exposure to UV light. For instance, afterthe UV-curable composition is applied to the medical device, thecomposition can be cured within seconds or minutes, depending on theformulation and curing conditions. In another example, the antimicrobialsolution can be cured relatively quickly by exposure to heat (e.g.,infrared heat). Indeed, under certain circumstances, the solution can beheat-cured at about 100° Celsius (C.) in about 5 minutes or less.

While the methods of the present invention have proven to beparticularly useful in the area of coating IV access devices, thoseskilled in the art will appreciate that the described methods can beused for a variety of different applications in a variety of differentareas of manufacture that include coating an object with anantimicrobial coating.

These and other features and advantages of the present invention will beset forth or will become more fully apparent in the description thatfollows and in the appended claims. The features and advantages may berealized and obtained by means of the instruments and combinationsparticularly pointed out in the appended claims. Furthermore, thefeatures and advantages of the intention may be learned by the practiceof the invention or will be obvious from the description, as set forthhereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

In order that the manner in which the above-recited and other featuresand advantages of the invention are obtained and will be readilyunderstood, a more particular description of the invention brieflydescribed above will be rendered by reference to specific embodimentsthereof, which are illustrated in the appended drawings. Understandingthat these drawings depict only typical embodiments of the invention andare not, therefore, to be considered to be limiting of its scope, theinvention will be described and explained with additional specificityand detail through the use of the accompanying drawings in which:

FIG. 1 illustrates a block diagram of a representative embodiment of amethod for coating a medical device with an antimicrobial coating;

FIG. 2 illustrates a block diagram of a representative embodiment of themethod for coating a medical device with an antimicrobial coating;

FIG. 3 illustrates a perspective view of a representative embodiment ofan IV access device;

FIG. 4A illustrates a perspective view of a representative embodiment ofa system for applying an antimicrobial coating to a medical device; and

FIG. 4B illustrates a perspective view of a representative pallet forholding a medical device during operation of the system shown in FIG.4A.

DETAILED DESCRIPTION OF THE INVENTION

The described invention relates to methods and compositions for coatingone or more surfaces of a medical device with an antimicrobial coating.Once the antimicrobial coating is cured onto the medical device, anantimicrobial agent in the coating can gradually diffuse out of thecoating when the coating is softened by IV fluids or other types offluids. Accordingly, microbes that come into contact with the coatedsurface of the medical device can be killed and the medical device mayremain sanitary for a prolonged period of time.

FIG. 1 illustrates a representative embodiment of the described coatingmethods. Specifically, FIG. 1 shows that the method 10 for coating amedical device with an antimicrobial coating generally comprisesproviding a medical device 12, dispensing an antimicrobial coating ontothe device 14, flushing excess coating from the device 16, and curingthe coating to the device. In order to provide a better understanding ofthe described coating method, the following disclosure provides a moredetailed disclosure of medical devices and antimicrobial coatings thatcan be used with the coating method, the various stages of method, andsystems for performing the method.

With respect to the types of medical devices that can be used with thedescribed coating methods, the methods can be used with any suitablemedical device, including, but not limited to, an IV access device,medical tubing, a catheter assembly, and any other viable medical-gradeinstrument that contacts fluids flowing into or out of a patient.

The medical device can comprise any material that is suitable for usewith the described methods. In some typical embodiments, however, themedical device comprises one or more polymeric substrates. For instance,the medical device can comprise one or more polycarbonates,polyurethanes, polyvinyl chlorides, silicones, PET plastics,styrene-butadiene rubbers, acrylics, and combinations thereof.

The antimicrobial coating can comprise any suitable antimicrobialcomposition that is suitable for use on the medical device.Nevertheless, in preferred embodiments, the antimicrobial coating isselected from a UV-curable, antimicrobial composition and anantimicrobial solution. To provide a better understanding of theUV-curable composition and the antimicrobial solution, each is discussedbelow in more detail.

In some currently preferred embodiments, the antimicrobial coatingcomprises the UV-curable, antimicrobial composition. In suchembodiments, the UV-curable composition may comprise any suitableingredient. In one aspect of the invention, the UV-curable coatingcomprises materials (referred to herein the UV-curable material) thatare capable of forming a UV-curable polymer composition. While theUV-curable material may comprise any suitable ingredient, in somepreferred embodiments, the UV-curable material comprises one or moreoligomers, monomers, and photoinitiators. In addition to the UV-curablematerial, the UV-curable composition further comprises an effectiveantimicrobial agent. The various ingredients that are added together toform the UV-curable composition are described below. In the followingdiscussion, the UV-curable material will comprise 100 parts by weight.Additionally, the ingredients added to the UV-curable material to formthe UV-curable composition will be defined in parts by weight added to100 parts by weight of the UV-curable material.

The UV-curable material may comprise any oligomer that is compatiblewith the other components of the UV-curable composition and that isusable within the scope of the present invention. Nevertheless, theoligomer is generally selected from one or more acrylated aliphaticurethanes, acrylated aromatic urethanes, acrylated polyesters,unsaturated polyesters, acrylated polyethers, acrylated acrylics, andthe like, or combinations thereof. Indeed, in some embodiments, theUV-curable coating comprises a urethane- or polyester-type acrylate,such as 7104, 7101, 7124-K, 7105-5K from Electronic Materials Inc. (EMI)(EM Breckenridge, Co.), 1168-M, 1-20781 from Dymax Corporation(Torrington, Conn.), or UV 630 from Permabond Engineering Adhesives(Somerset, N.J.). Where the oligomer comprises an acrylated functionalgroup, the functional group is preferably selected from amono-functional, di-functional, tri-functional, tetra-functional,penta-functional, and hexa-functional acrylate.

The oligomer may account for any suitable portion of the UV-curablematerial. Typically, however, the oligomer will comprise from about 10%to about 90% of the UV-curable material. In some preferred embodiments,the oligomer comprises from about 20% to about 80% of the UV-curablematerial. In certain other embodiments, however, the oligomer comprisesfrom about 30% to about 70% of the UV-curable material.

While the monomer in the UV-curable material can be selected from anymonomer that is compatible with the other components of the UV-curablecomposition and that is usable within the scope of the invention, themonomer is preferably selected from 2-ethyl hexyl acrylate, isooctylacrylate, isobomylacrylate, 1,6-hexanediol diacrylate, diethylene glycoldiacrylate, triethylene glycol diacrylate, pentaerythritol tetraacrylate, penta erythritol tri acrylate, dimethoxy phenyl acetophenonehexyl methyl acrylate, 1,6 hexanidiol methacrylate, and the like, orcombinations of these compounds.

In typical embodiments, the monomer comprises from about 5% to about 90%of the UV-curable material. In other embodiments, however, the monomercomprises from about 10% to about 75% of the UV-curable material. Instill other embodiments, the monomer comprises from about 20% to about60% of the UV-curable material.

The photoinitiator can comprise any photoinitiator that is compatiblewith the other components of the UV-curable composition (i.e., theUV-curable material) and that is usable within the scope of theinvention. Generally, the photoinitiator is selected from either asingle molecule cleavage type photoinitiator, such as one or morebenzoin ethers, acetophenones, benzoyl oximes, and acyl phosphineoxides; or a hydrogen abstraction type of photoinitiator, such asMichler's ketone, thioxanthone, anthroguionone, benzophenone, methyldiethanol amine, and 2-N-butoxyethyl-4-(dimethylamino) benzoate.

The photoinitiator typically comprises from about 0.5% to about 10% ofthe UV-curable material. Indeed, in some embodiments, the photoinitiatorcomprises from about 1% to about 8.5% of the UV-curable material. Instill other embodiments, the photoinitiator comprises from about 2% toabout 7% of the UV-curable material.

The antimicrobial agent can comprise any antimicrobial agent that iscompatible with the other components of the UV-curable composition andthat is usable within the scope of the invention. Additionally, in someembodiments, the antimicrobial agent comprises an agent that eitherdissolves in the UV-curable composition or can be uniformly distributedtherein. Accordingly, in such embodiments, sufficient antimicrobialagent can migrate within the UV-curable composition to contact thelocation of microbial activity. In any event, it is preferred that theantimicrobial agent not react chemically with the other components ofthe UV-curable composition. Some examples of antimicrobial agents thatare suitable for use with the UV-curable composition include one or morealdehydes, anilides, biguanides, silver, silver compound, bis-phenols,and quaternary ammonium compounds.

The antimicrobial agent is generally present in the UV-curablecomposition in the amount of from about 0.5 to about 50 parts, byweight, in comparison to 100 parts by weight of the UV-curable material.In other embodiments, the antimicrobial agent is present in theUV-curable composition in the amount of from about 0.5 to about 30parts, by weight, in comparison to 100 parts of the UV-curable material.In further embodiments of the UV-curable composition, the antimicrobialagent is present in the amount of from about 0.5 to about 20 parts, byweight, in comparison to 100 parts of the UV-curable material.

In addition to the aforementioned materials, the UV-curable compositioncan comprise any other suitable component. Indeed, in certainembodiments, the UV-curable composition also includes a Theologicalmodifier to improve the composition's flow characteristics and to helpcomponents be uniformly distributed throughout the composition. In suchembodiments, the Theological modifier is preferably selected fromorganic clay, castor wax, polyamide wax, polyurethane, and fumed silica.Additionally, in such embodiments, the Theological modifier generallycomprises from about 0.1 to about 30 parts, by weight, added to 100parts, by weight, of the UV-curable material (i.e. the UV-curablematerial is 100 weight units, while the Theological modifier comprisesfrom about 0.1 to about 30 parts of additional weight that is added tothe 100 parts of the UV-curable material). In other embodiments, theTheological modifier comprises from 0.1 to about 20 parts by weightcompared to 100 parts by weight of the UV-curable material. In certainfurther embodiments, the rheological modifier comprises from about 0.2to about 10 parts by weight compared to 100 parts by weight of theUV-curable material.

The UV-curable composition may also have any other suitablecharacteristic. For instance, in some embodiments, the UV-curablecomposition has a viscosity that is less than about 10,000 centipoises(cps). In other embodiments, the viscosity of the UV-curable compositionis below about 5,000 cps. In some presently preferred embodiments, theUV-curable composition has a viscosity that is between about 20 andabout 1,000 cps.

While the UV-curable composition has been described above withspecificity, a more detailed description of the UV-curable compositionis found in U.S. patent application Ser. No. 12/397,760, filed Mar. 4,2009, and entitled “Antimicrobial Compositions;” the entire disclosureof which is hereby incorporated by reference.

Where the antimicrobial coating comprises an antimicrobial solution, thesolution may comprise any suitable ingredient. In some embodiments, theantibacterial solution comprises an acrylate polymer or copolymer, asolvent, and an antimicrobial agent. To provide a better understandingof the antimicrobial solution, each of its aforementioned ingredients isdescribed below in more detail.

The acrylate polymer or copolymer can comprise any acrylate polymerand/or copolymer that is compatible with the other components of theantimicrobial solution and that is usable within the scope of theinvention. In some embodiments, the acrylate-type polymer, copolymer, orpolymer resin is insoluble in water while being soluble in one or moreof the solvents that are discussed hereinafter. For example, theacrylate polymer or copolymer is generally selected from one or morealkyl acrylates, alkyl methacryloates, alkyl hydroxyl (meth) acrylates,and alkyl methoxycinnamate acrylates. In this example, the acrylate canbe alkyl acrylate, alkyl hydroxyl (meth) acrylate, or alkylmethacrylate. Additionally, in this example, the alkyl group can have acarbon number from 0 to 22, wherein 0 means hydrogen, 1 means a methylgroup, 2 means an ethyl group, 3 means a propyl group, etc.), butpreferably a number from 0 to 6, and more preferably from 0 to 3.

The solvent in the antimicrobial solution can comprise any solvent thatis compatible with the other components of the antimicrobial solutionand that allows the solution to function as intended. For instance, thesolvent may comprise one or more of a variety of solvents that arecapable of dissolving the aforementioned acrylate polymer or copolymer.Some examples of suitable solvents include one or more low molecularweight alcohols, low molecular weight alkanes, simple ketones, andcombinations thereof. Some examples of suitable low molecular weightalcohols comprise alcohols having from 1 to 6 carbons (e.g., methanol,ethanol, propanol, isopropanol, and butanol). Because methanolevaporates relatively quickly, however, methanol may not be preferred inall embodiments. Instead, in some currently preferred embodiments, thesolvent comprises ethanol or isopropanol. Some suitable examples ofsuitable low molecular weight alkanes comprise alkanes having from 5 to7 carbons (e.g., pentane, hexane, heptane, and isomers thereof). Indeed,in some preferred embodiments the solvent comprises hexane and/orheptane. Additionally, an example of a suitable simple ketone isacetone. It should be noted, however, that in some embodiments thatcomprises acetone, the solvent preferably also comprises anothersolvent, such as an alcohol or an alkane.

While the solvent may comprise any suitable amount of the antimicrobialsolution, in some embodiments, the solvent comprises less than about 67%of the dry weight of the antimicrobial solution. For instance, where thepolymer accounts for about 60%±10% of the antimicrobial solution, thesolvent can account for less than about 40%±10% of the solution. Inother embodiments, however, the solvent comprises less than about 50% ofthe dry weight of the composition. In still other embodiments, thesolvent comprises less than about 40% of the dry weight of thecomposition.

The antimicrobial agent in the antimicrobial solution can comprise anyantimicrobial agent that is compatible with the other components of thesolution and that allows the solution to function as intended. Indeed,the antimicrobial agent for the antimicrobial solution is generallyselected from one or more aldehydes, anilides, biguanides, silver,silver compounds, bis-pheonols, and quaternary ammonium compounds. Incertain instances, the antimicrobial agent is preferably selected fromcetyl pyridium chloride, cetrimide, benzalkonium chloride, alexidine,chlorexidine diacetate, and o-phthalaldehyde.

While the antimicrobial agent may comprise any suitable amount of theantimicrobial solution, in some embodiments, the antimicrobial agentcomprises less than about 50% of the dry weight of the solution. Inother embodiments, the antimicrobial comprises less than about 30% ofthe dry weight of the antimicrobial solution. In still otherembodiments, the antimicrobial agent comprises about 0.5% and about 20%of the dry weight of the antimicrobial solution.

In addition to the aforementioned ingredients, the antimicrobialsolution may comprise any other suitable ingredient. Indeed, in someembodiments, the antimicrobial solution comprises a Theological modifierthat is generally selected from organic clay, castor wax, polyamide wax,polyurethane, and fumed silica. In such embodiments, the Theologicalmodifier is generally present in an amount of from about 0.2% to about30% of the dry weight of the antimicrobial solution. That is, the weightof the composition once the solvent has evaporated. In certain otherembodiments, the rheological modifier is present in the amount of fromabout 0.2% to about 20% of the dry weight of the antimicrobial solution.In certain other embodiments, the rheological modifier is present in anamount of from about 0.2% to about 10% of the dry weight of theantimicrobial solution.

While the antimicrobial solution has been described above withspecificity, a more detailed description of the antimicrobial solutionis found in U.S. patent application Ser. No. 12/476,997, filed Jun. 2,2009, and entitled “Antimicrobial Coating Compositions;” the entiredisclosure of which is hereby incorporated by reference.

The described methods can be performed or modified in any suitablemanner. By way of example, FIG. 2 illustrates one presently preferredembodiment of the described method for coating a medical device.Specifically, FIG. 2 shows an example in which the method 11 begins at12 by providing a medical device.

Next, at 13, FIG. 2 shows the method 10 optionally includes masking oneor more desired portions of the medical device to prevent theantimicrobial coating from contacting the masked portion(s). By way ofillustration, FIG. 3 shows that where the medical device comprises aportion of an IV access device 100 (e.g., BECTON DICKINSON's Q-SYTE® IVaccess device) having a Luer component 102, the Luer component 102 canbe inserted into a medical-grade tube 104 so that the external surfaceof the Luer 102 is prevented from being coated with the antimicrobialcoating.

Returning back to FIG. 2, box 14 shows that the method 10 continues bydispensing the antimicrobial coating (e.g., the UV-curable compositionor the antimicrobial solution) onto the medical device. Any suitableamount of the antimicrobial coating can be dispensed onto the desiredsurface(s) of the medical device. For example, where the medical devicecomprises the IV access device of FIG. 3, between about 0.01 and about0.05 grams of the antimicrobial coating can be dispensed into thedevice's inner lumen 106. In still another example, where the medicaldevice comprises the IV access device of FIG. 3, between 0.02 and about0.04 grams of antimicrobial coating are dispensed into the device'sinner lumen.

After the antimicrobial coating has been dispensed onto the medicaldevice, box 16 of FIG. 2 shows that any excess coating on the device isflushed or otherwise removed from the medical device. In this manner,the antimicrobial coating can be caused to have a uniform thicknessacross the coated surface. The excess coating can be removed in anysuitable manner, including by blowing an inert gas across the coatedsurface of the medical device, spinning the medical device in acentrifuge, by allowing excess material to drip from the device due tothe pull of gravity, etc. Nevertheless, in some presently preferredembodiments, a pressured inert gas, such as nitrogen, helium, or argon,is blown across the coated surface. By way of example, where the medicaldevice comprises the IV access device 100 of FIG. 3, an insert gas, suchas nitrogen, with an air pressure of between about 5 and about 25 poundsper square inch (psi) (e.g., 10 psi±5 psi) is preferably blown past thecoated surface.

In order to reduce the amount of antimicrobial coating that is wastedduring the described method, box 17 of FIG. 2 shows that the excessantimicrobial coating that is flushed from the medical device isoptionally collected and recycled. In other words, the excessantimicrobial coating can be collected and be used to coat anothermedical device.

With the excess antimicrobial coating removed from the medical device,boxes 20 and 22 show that the coating left on the device is cured. Whilethe antimicrobial coating can be cured in any suitable manner, box 20shows that in some embodiments where the antimicrobial coating comprisesthe UV-curable composition, the UV-curable composition is cured by beingexposed to UV light. In such embodiments, the UV-curable composition canbe exposed to any suitable wavelength of UV light. In one example, theUV-curable composition is exposed to UV light with a wavelength ofbetween about 320 to about 500 nm. In another example, the UV-curablecomposition is cross-linked by being exposed to light with a wavelengthof between about 350 and about 450 nm.

Additionally, the UV-curable composition can be exposed to the UV lightfor any amount of time that allows the UV-curable composition to dry andbe cured to the medical device. Indeed, in one example, the UV-curablecomposition is cured after less than about 1 minute of exposure to theUV light. In another example, the UV-curable coating is cured after lessthan about 30 seconds of exposure to the UV light. In still anotherexample, the UV-curable coating is cured after less than about 10seconds of exposure to the UV light. In a final example, the UV-curablecoating is cured after less than about 4 seconds of exposure to the UVlight.

Referring now to box 22, FIG. 2 shows that in some embodiments where theantimicrobial coating comprises the antimicrobial solution, the solutionis cured through exposure to heat from a heat source (e.g., an infraredheater, a convectional heater, a conventional heater, etc.). In suchembodiments, the antimicrobial solution coating the device can be curedat any suitable temperature. In one example, the solution is cured at atemperature of less than about 120° C. In another example, theantimicrobial solution is cured at a temperature of less than about 100°C. In still another example, the antimicrobial solution is cured at atemperature of less than about 60° C.

While the antimicrobial solution can be cured in any suitable amount oftime, under certain conditions, the solution is cured after less thanabout 10 minutes of exposure to a temperature of less than about 60° C.Similarly, under certain conditions, the antimicrobial solution is curedafter less than about 5 minutes of exposure to a temperature of lessthan about 100° C.

Once the antimicrobial coating is cured, box 24 of FIG. 2 shows that anymasking material is optionally removed from the medical device. At thatpoint, the medical device can be used and the antimicrobial coating canbe effective almost immediately after being exposed to a fluid (e.g., anIV fluid).

The described methods can be performed by any suitable system and/orapparatus that is capable of performing one or more of the featuresillustrated in FIG. 2. Indeed, in some embodiments, at least a portionof the described methods are performed by medical device coating system.While such a system can comprise any suitable component orcharacteristic, FIG. 4A illustrates a representative embodiment in whichthe medical device coating system 200 comprises a medical device pallet202, a top slide 204 having coating-dispending heads 206 andgas-dispensing heads 208, coating valves 210, gas valves 212, a gasreservoir 214, excess funnels 216, and a pressurized coating reservoir218.

While the medical device coating system may be used in any suitablemanner, in order to provide a better understanding of the system, atypical example of its use is provided herein. Specifically, FIG. 4Bshows that one or more medical devices, such as the IV access device100, can be placed on the medical device pallet 202 so that an opening108 to the inner lumen 106 of the device 100 is facing towards acoating-dispensing head 206 (shown in FIG. 4A).

In order to ensure that the medical device stays in a proper orientationthrough the coating process, the pallet may secure the medical device ina desired orientation, in any suitable manner. By way of illustration,FIG. 4B shows an embodiment in which the IV access device 100 is securedto the pallet 202 when a lip 110 on the access device 100 is slid into agroove 220 on the pallet 202.

With the medical devices secured to the pallet 202, FIG. 4A shows thatthe pallet 202 is placed beneath the top slide 204. At this point, thetop slide 204 may move with respect to the pallet 202 so that a coatingdispensing head 206 is disposed above the opening of each device (notshown in FIG. 4A).

Once the dispensing heads are aligned with the surface of the medicaldevice that is to be coated, the coating valves 210 are opened to allowa predetermined amount (e.g., between about 0.01 and about 0.05 g) ofantimicrobial coating to be squirt from the pressurized coatingreservoir 218, through the coating-dispensing heads 206, and onto themedical device. While this dispensing process can take any suitableamount of time, in some instances, the dispensing process takes aslittle as 4 seconds or less (e.g., about 2 seconds+1 second).

After the coating has been dispensed, the top slide 204 moves in thedirection of arrow 222 so that a gas-dispensing head 208 is disposedabove the coated surface of each medical device. Once the gas-dispensingheads are properly aligned, the top slide 204 moves in the direction ofarrow 224 so that the gas-dispensing heads 208 form a seal against themedical device's opening (not shown in FIG. 4A). Once a seal is formed,the gas valves 212 open to allow a controlled amount of the inert gas,at a controlled pressure, to flush any excess coating from the medicaldevice. This excess coating is then collected in the excess funnels 216,which direct the excess coating back to the pressurized coatingreservoir 218 for future use.

With the excess coating removed from the medical devices, the pallet 202can be removed from beneath the top slide 204 and be placed in a curingchamber (not shown), such as a UV-light chamber or a heatedchamber-depending on composition of the antimicrobial coating.

Following the curing process, the medical devices are removed from thepallet and new batch of uncoated medical devices can be placed in thepallet so that the process can be repeated.

The described system can be modified in any suitable manner. In oneexample, while FIG. 4A shows an embodiment in which the system 200 isconfigured to coat 4 medical devices simultaneously, the system canmodified to simultaneously coat any suitable number of medical devices.For instance, the system can be modified to coat 1, 2, 3, 5, 6, 7, 8, ormore medical devices, simultaneously. In another example, instead ofcomprising a coating-dispensing head and a separate gas-dispensing head,the antimicrobial coating and the inert gas may be dispensed to amedical device through single head so as to speed the time between thedispensing and flushing portions of the method. In yet anotherembodiment, the pallet, the gas dispensing head, or some other componentin proximity to the medical devices can comprise a UV light source. Insuch embodiments, the system can cure the medical devices withoutrequiring the pallet to be removed from a location beneath the topslide.

As discussed above, the described methods, apparatus, and compositionshave several beneficial characteristics. In one example, the describedmethods allow a medical device to be coated with an antimicrobialcoating (e.g., the UV-curable composition) in a relatively short periodof time. For instance, instead of taking several hours (e.g., 24) tocure a harsh solvent (e.g., THF or DMF) onto a medical device, theUV-curable coating and the antimicrobial solution can be cured onto amedical device in a few second or minutes, respectively. Indeed, in someembodiments in which the antimicrobial coating comprises the UV-curablecomposition, the composition can be dispensed, flushed, and cured withinabout 30 seconds. In some preferred embodiments, the UV-curablecomposition can be dispensed, flushed, and cured within about 10seconds. Similarly, in some embodiments in which the antimicrobialcoating comprises the antimicrobial solution, the solution is dispensed,flushed, and cured within about 10 minutes. In some presently preferredembodiments, however, the antimicrobial solution is dispensed, flushed,and cured in less than about 5 minutes.

In another example of a beneficial characteristic of the describedmethods, the methods can allow the antimicrobial coating to be appliedto the medical device with a substantially uniform coating thickness. Instill another example, because the described methods allow for excessantimicrobial coating to be recycled, the described methods may use lessantimicrobial coating, overall, than certain conventional coatingtechniques.

In yet another example, the described UV-curable and antimicrobialsolutions provide several advantages over certain known antimicrobialcoatings. For instance, the UV-curable and antimicrobial solutions canbe less toxic, less expensive, more environmentally friendly, cause lessdeformation or cracking to a medical device, be more aestheticallypleasing, and require less-expensive equipment than do several competingantimicrobial coatings (e.g., THF and DMF).

The present invention may be embodied in other specific forms withoutdeparting from its structures, methods, or other essentialcharacteristics as broadly described herein and claimed hereinafter. Thedescribed embodiments and examples are to be considered in all respectsonly as illustrative, and not restrictive. The scope of the inventionis, therefore, indicated by the appended claims, rather than by theforegoing description. All changes that come within the meaning andrange of equivalency of the claims are to be embraced within theirscope.

1. A method for applying an antimicrobial coating to a medical device, the method comprising: providing a first medical device; dispensing an antimicrobial coating onto the first device, wherein the coating is selected from: a) a UV-curable, antimicrobial composition, and b) an antimicrobial solution comprising an acrylate polymer or copolymer; flushing an excess amount of the coating from the first device; and curing the coating.
 2. The method of claim 1, wherein the UV-curable composition comprises: a photoinitiator; an oligomer; a monomer; a Theological modifier; and an antimicrobial agent.
 3. The method of claim 2, wherein the photoinitiator is selected from the group consisting of benzoin ether, acetophenone, benzoyl oxime, acyl phosphine oxide, Michler's ketone, thioxanthone, anthroguionone, benzophenone, methyl diethanol amine, 2-N-butoxyethyl-4-(dimethylamino) benzoate, and combinations thereof.
 4. The method of claim 2, wherein the oligomer is selected from an acrylated aliphatic urethane, an acrylated aromatic urethane, an acrylated polyester, an unsaturated polyester, an acrylated polyether, an acrylated acrylic, and combinations thereof.
 5. The method of claim 2, wherein the monomer is selected from the group consisting of 2-ethyl hexyl acrylate, isooctyl acrylate, isobomylacrylate, 1,6-hexanediol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, pentaerythritol tetra acrylate, penta erythritol tri acrylate, dimethoxy phenyl acetophenone hexyl methyl acrylate, 1,6 hexanidiol methacrylate, and combinations thereof.
 6. The method of claim 1, wherein the antimicrobial solution further comprises: a solvent selected from an alcohol having from 1 to 6 carbons, an alkane having from 1 to 6 carbons, acetone, and combinations thereof; a rheological modifier; and an antimicrobial agent.
 7. The method of claim 6, wherein the acrylate polymer or copolymer is selected from the group consisting of an alkyl acrylate, an alkyl methacrylate, an alkyl hydroxyl (meth) acrylate, an alkyl methoxycinnamate, and combinations thereof.
 8. The method of claim, 1 wherein the flushing of the excess coating comprises blowing the excess coating from the device with a pressurized, inert gas.
 9. The method of claim 8, wherein the excess coating is recycled and dispensed onto a second medical device.
 10. The method of claim 1, wherein the curing of the coating comprises exposing the first device having the UV-curable composition disposed thereon to UV light.
 11. The method of claim 1, wherein the curing comprises exposing the first device having the antimicrobial solution to heat.
 12. A method for applying an antimicrobial coating to a medical device, the method comprising: providing a medical device; dispensing a UV-curable, antimicrobial composition onto the medical device, wherein the coating comprises an oligomer, a monomer, a photoinitiator, a Theological modifier, and an antimicrobial agent; flushing an excess amount of the composition from the device; and curing the composition by exposing the composition to UV light.
 13. The method of claim 12, wherein the dispensing, flushing, and curing of the composition is completed in less than about 30 seconds.
 14. The method of claim 12, wherein the dispensing, the flushing, and the curing of the composition is completed in less than about 10 seconds.
 15. A method for applying an antimicrobial coating to a medical device, the method comprising: providing a medical device; dispensing an antimicrobial solution onto the medical device; flushing an excess amount of the composition from the device; and curing the composition with a heat source, wherein the antimicrobial solution comprises an acrylate polymer or acrylate copolymer.
 16. The method of claim 15, wherein the antimicrobial solution further comprises a solvent selected from an alcohol having from 1 to 6 carbons, an alkane having from 1 to 6 carbons, acetone, and combinations thereof.
 17. The method of claim 15, wherein the antimicrobial solution further comprises a Theological modifier and an antimicrobial agent.
 18. The method of claim 15, wherein the dispensing, flushing, and curing of the composition are completed in less than about 10 minutes.
 19. The method of claim 15, wherein the dispensing, flushing, and curing of the composition are completed in less than about 5 minutes.
 20. The method of claim 17, wherein the antimicrobial agent is selected from cetyl pyridium chloride, cetrimide, benzalkonium chloride, alexidine, chlorhexidine diacetate, phthalaldehyde, and combinations thereof. 